UltraGas boilers are renowned for their reliability and performance. However, like any advanced heating system, occasional issues may arise. To help you resolve minor problems quickly, we’ve put together this expert guide with troubleshooting tips and quick fixes

If you’re unable to resolve the issue using these steps, our technical support team is available to assist you. Plus, our service engineers have in-depth knowledge of Hoval equipment and can help with maintenance and servicing needs. 

If your UltraGas boiler needs resetting, follow these steps: 

• Locate the reset button, which is recessed and either behind the Hoval badge or inside the small door with the on/off rocker switch. 
• Press and hold the reset button for a few seconds. 
• Your boiler should restart. 

For more details, refer to your operator’s manual. 

This happens when the boiler is powered up and the screen is touched too soon, causing the system to default to the domestic display instead of the commercial/industrial screen. 

How to Fix It: 

• You’ll need to recalibrate the screen and restore the correct display mode. 
• Contact our technical team for Application Note TTE App 046, which includes step-by-step calibration instructions and an access code. 
   

An E18 fault occurs when the fan speed is lower than expected. This is typically caused by a sticky air inlet damper mechanism. 

Troubleshooting Steps: 

✔ Check if your boiler has an air inlet damper (UltraGas D, 2D, or optional on single UltraGas units). 
✔ The burner fan power runs through the damper actuator—if the damper sticks, the fan won’t receive power. 

To fix this: 

• Strip and lubricate the damper mechanism as outlined in the manual. 
• Reassemble and test to ensure free movement. 
• Reset the boiler and check if the issue is resolved. 

Regular maintenance can prevent this issue from occurring in the future. 

Confirming that there is power on the fan, and removing the connecting low voltage lead should allow it to ramp up and operate at its maximum speed.  

These faults indicate that the ionisation current from the flame probe is too low. Before replacing the probes, follow these steps: 

If you're still experiencing issues after following these troubleshooting steps, our technical support team is available to assist you. Please have the boiler serial number to hand when doing this.   Additionally, our service engineers specialise in Hoval equipment and can provide in-depth maintenance support to keep your system running efficiently. 

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